The present invention relates to an image forming method which can protect an image of a record produced by a nonsilver photographic color hard copy recording system, such as an electrophotographic recording system, an ink jet recording system, or a thermal transfer recording system, particularly by an electrophotographic system or an ink melt transfer system (a hot-melt transfer system), can impart weathering resistance and the like to the image, can enhance surface gloss of the image, and, at the same time, can prepare records having high image sharpness and image quality comparable to silver salt photographs, and also relates to records obtained therefrom.
By virtue of the advance of digital cameras and color hard copy technology in recent years, prints having full-color images formed thereon by a nonsilver photographic system, such as an electrophotographic recording system, an ink jet recording system, or a thermal transfer recording system, could have become immediately prepared in situ as the need arises, as opposed to a conventional method wherein a person asks a processing laboratory for development and receives prints later from the processing laboratory.
In these color copy prints, however, images blur upon contact with water, chemicals or the like located close thereto. Further, upon rubbing against hard objects, images are disadvantageously separated or smeared. In addition, in these prints formed particularly by an electrophotographic system or a hot-melt transfer system, the recorded portion rises, and concaves and convexes are formed on the surface of the prints. Therefore, the quality of the prints is much lower than that of photographs having a suitable level of glossiness and a suitable level of sharpness.
For example, in the electrophotographic recording system, a toner image is transferred onto an image-receiving object, the toner is melted by a hot roll, and the melted toner is self-cooled to adhere and fix the cooled toner onto the image-receiving object. In this system, concaves and convexes are formed on the surface of the fixed image, and, thus, the smoothness is low and a suitable level of glossiness and a suitable level of sharpness cannot be provided. On the other hand, Japanese Patent Laid-Open No. 29852/1986 proposes a method wherein an acryl-modified alkyd resin solution is coated on an image formed by an electrophotographic process and the coating is then dried to form a glossy fixed image. Japanese Patent Laid-Open No. 278967/1992 proposes a method for forming deep images wherein the surface of the transfer material is covered with a transparent toner. Further, Japanese Patent Laid-Open No. 224779/1983 proposes a recording apparatus wherein a laminate material with a hot-melt adhesive is heated together with a recorded material to apply the laminate material to the recorded material.
Thus, various proposals have hitherto been made. In output prints formed particularly by an electrophotographic recording system or a hot-melt transfer system wherein the surface of prints rises, however, at the present time, in any event, the above-described post treatment cannot always provide desired photograph-like image quality.
In view of the above problems of the prior art, the present invention has been made, and it is an object of the present invention to provide an image forming method which can protect an image of a record, which can be immediately produced by a nonsilver photographic color hard copy recording system, can impart weathering resistance and the like to the image, can enhance surface gloss to the image, and, at the same time, can prepare records having high image sharpness and image quality comparable to silver salt photographs, and to provide a record obtained therefrom.
First Invention
The above object can be attained by an image forming method according to the first invention which comprises the steps of:
providing a print output by a nonsilver photographic color hard copy recording system;
providing a protective layer transfer sheet comprising a thermally transferable protective layer having a single or multi-layer structure separably provided on a substrate sheet;
putting the print and the protective layer transfer sheet on top of each other and thermally transferring the protective layer onto an image in the print so as to cover at least the printed portion in the print; and
then separating the substrate sheet from the protective layer transfer sheet.
Preferably, the nonsilver photographic color hard copy recording system is any one of an electrophotographic recording system, an ink jet recording system, and a thermal transfer recording system.
The protective layer transfer sheet preferably comprises: a substrate sheet; and, stacked on the substrate sheet in the following order, a thermally transferable release layer having a single or multi-layer structure and a thermally transferable protective layer having a single or multi-layer structure.
The protective layer transfer sheet preferably comprises: a substrate sheet; and, stacked on the substrate sheet in the following order, a thermally transferable release layer having a single or multi-layer structure, a thermally transferable protective layer having a single or multi-layer structure, and a thermally transferable adhesive layer having a single or multi-layer structure.
Further, the substrate sheet in the protective layer transfer sheet is preferably formed of a 2 to 100 xcexcm-thick plastic film.
The plastic film preferably has a specular glossiness at 45 degrees of not more than 100%.
Here this specular glossiness is a value as measured under conditions specified in JIS Z 8741.
The coverage of the whole layer to be transferred in the protective layer transfer sheet is preferably 3 to 30 g/m2. According to this constitution, the concaves and the convexes on the surface of the image can be flattened to impart a high level of glossiness to the image. Here the coverage is on a dry basis.
The material used in the thermally transferable protective layer is preferably a thermoplastic resin.
The thermoplastic resin preferably has a Tg value of 40 to 100xc2x0 C. and a storage modulus at 110xc2x0 C. of not more than 1xc3x97105 Pa.
According to the present invention, there is provided a protective layer transfer sheet for use in providing any one of the above image forming methods.
Further, according to the present invention, there is provided a record comprising a protective layer provided on the image of the print by any one of the above image forming methods.
The record produced by any one of the above image forming methods has a specular glossiness at 45 degrees in the range of 70 to 110%. Here this specular glossiness is a value as measured under conditions specified in JIS Z 8741.
According to the image forming method comprising the steps of: providing a print output using a nonsilver photographic color hard copy recording system; providing a protective layer transfer sheet comprising a thermally transferable protective layer separably provided on a substrate sheet; putting the print and the protective layer transfer sheet on top of each other and thermally transferring the protective layer onto an image in the print; and then separating the substrate sheet from the protective layer transfer sheet, the concaves and the convexes on the surface of the image can be flattened by the transferred protective layer to impart a high level of glossiness to the image. Further, unlike film laminates, it is possible to eliminate the necessity of significantly increasing the thickness of records, and records can be realized which have image quality comparable to that of silver salt photographs.
Second Invention
According to the second invention, there is provided an image forming method comprising the steps of:
providing a protective layer transfer sheet comprising a thermally transferable protective layer having a single or multi-layer structure separably provided on a substrate sheet;
providing a print output by a nonsilver photographic color hard copy recording system;
putting the protective layer transfer sheet onto the print and thermally transferring the protective layer onto an image in the print so as to cover at least the printed portion; and
then separating the substrate sheet from the protective layer transfer sheet,
the thermally transferable protective layer in the protective layer transfer sheet being composed mainly of a thermoplastic resin.
The thermoplastic resin preferably contains at least one member selected from the group consisting of polyester resins, epoxy resins, and phenoxy resins.
The thermoplastic resin preferably has a glass transition temperature of 40 to 80xc2x0 C.
The thermoplastic resin preferably has a weight average molecular weight (Mw) of not more than 20000 and a number average molecular weight (Mn) of not more than 10000.
The thermoplastic resin preferably comprises two or more types of thermoplastic resins different from each other in number average molecular weight.
Further, preferably, one type of the thermoplastic resin constitutes a main component of the thermoplastic resin and has a number average molecular weight of not more than 10000 while the other type has a number average molecular weight of not less than 10000.
Preferably, a release layer is further provided between the thermally transferable protective layer and the substrate film.
The release layer is preferably composed mainly of an acrylic resin having a number average molecular weight of not more than 40000.
The thermally transferable protective layer preferably contains an ultraviolet absorber.
According to the present invention, there is provided a protective layer transfer sheet for use in providing any one of the image forming methods.
Further, according to the present invention, there is provided a record comprising a protective layer provided on an image of a print by any one of the image forming methods.
According to the image forming method comprising the steps of: providing a protective layer transfer sheet comprising a thermally transferable protective layer having a single or multi-layer structure separably provided on a substrate sheet; providing a print output by a nonsilver photographic color hard copy recording system; putting the protective layer transfer sheet onto the print and thermally transferring the protective layer onto an image in the print so as to cover at least the printed portion; and then separating the substrate sheet from the protective layer transfer sheet, the thermally transferable protective layer in the protective layer transfer sheet being composed mainly of a thermoplastic resin, the concaves and convexes on the surface of the image can be flattened by the transferred protective layer to impart a high level of glossiness to the image. Further, unlike film laminates, it is possible to eliminate the necessity of significantly increasing the thickness of records, and records can be realized which have image quality comparable to that of silver salt photographs.
Third Invention
According to the third invention, there is provided an image forming method comprising the steps of: providing a protective layer transfer sheet comprising a thermally transferable protective layer having a single or multi-layer structure separably provided on a substrate sheet; providing a print output by a nonsilver photographic color hard copy recording system; putting the protective layer transfer sheet onto the print and thermally transferring the protective layer onto an image in the print so as to cover at least the printed portion; and then separating the substrate sheet from the protective layer transfer sheet to form an image provided with a protective layer, the specular glossiness of the image provided with the protective layer being 65 to 110% as measured in the angle range of 45 to 75 degrees according to JIS Z 8741.
Further, according to the present invention, there is provided an image forming method comprising the steps of: providing a protective layer transfer sheet comprising a thermally transferable protective layer having a single or multi-layer structure separably provided on a substrate sheet; providing a print output by a nonsilver photographic color hard copy recording system; putting the protective layer transfer sheet onto the print and thermally transferring the protective layer onto an image in the print so as to cover at least the printed portion; and then separating the substrate sheet from the protective layer transfer sheet to form an image provided with a protective layer, the image in the print being a record of magenta gradation, the difference between the maximum value and the minimum value of the specular glossiness in the whole gradation region of the image provided with the protective layer after the transfer of the protective layer being not more than 20% as measured at 45 degrees according to JIS Z 8741.
According to the present invention, there is provided an image forming method comprising the steps of: providing a protective layer transfer sheet comprising a thermally transferable protective layer having a single or multi-layer structure separably provided on a substrate sheet; providing a print output by a nonsilver photographic color hard copy recording system; putting the protective layer transfer sheet onto the print and thermally transferring the protective layer onto an image in the print so as to cover at least the printed portion; and separating the substrate sheet from the protective layer transfer sheet to form an image provided with a protective layer, the image in the print being a record of magenta gradation, the difference between the maximum value and the minimum value of the specular glossiness in the whole gradation region of the image provided with the protective layer after the transfer of the protective layer as measured at 45 degrees according to JIS Z 8741 being not more than 50% of the difference between the maximum value and the minimum value of the specular glossiness in the whole gradation region of the image provided with the protective layer before the transfer of the protective layer as measured at 45 degrees according to JIS Z 8741.
The nonsilver photographic color hard copy recording system is preferably any one of an electrophotographic recording system, an ink jet recording system, and a thermal transfer recording system.
In the protective layer transfer sheet, the thermally transferable protective layer preferably contains an ultraviolet absorber.
According to the present invention, there is provided a protective layer transfer sheet for use in providing any one of the image forming methods.
Further, according to the present invention, there is provided a record comprising a protective layer provided on an image of a print by any one of the image forming methods.